Pipe joint

ABSTRACT

A joint between a manhole riser and a pipe feeding into the manhole includes a resilient gasket embedded in the riser and projecting radially into the opening through the wall of the riser to provide a seal against the outer surface of the intersecting pipe. Wire hoops are received in continuous grooves in the gasket to both stretch it outwardly and resist rolling of the gasket as the intersecting pipe is installed. Additionally, the opening through the riser wall includes an annular, inwardly projecting shoulder designed to support the intersecting pipe should the pipe shift with the respect to the riser, to thereby avoid the loss of seal that would result if the gasket itself supported the entire shear load.

United States Patent 1 91 1111 3,879,067

Keyser Apr. 22, 1975 [54] JOINT FOREIGN PATENTS OR APPLICATIONS 1 1lnvemofl Lewis Keyser, y Ohio 1.118.551 11/1961 Germany 285/1101,545,368 9/1968 France .-285/231 [73] Ass'gnee' Bmhers Company Damn1,218,062 1/1971 United Kingdom 285/230 200,867 11/1958 Germany 285/23122] Filed: Feb. 2, 1973 1 [211 App] No 329 217 Primary E.\-aminerThomasF. Callaghan Related U.S. Application Data Attorney, Agent, orFirm-Biebel, French & Bugg [57] ABSTRACT A joint between a manhole riserand a pipe feeding into the manhole includes a resilient gasket embeddedin the riser and projecting radially into the opening through the wallof the riser to provide a seal against the outer surface of theintersecting pipe. Wire hoops are received in continuous grooves in thegasket to both stretch it outwardly and resist rolling of the gasket asthe intersecting pipe is installed. Additionally, the opening throughthe riser wall includes an annular, inwardly projecting shoulderdesigned to support the intersecting pipe should the pipe shift with therespect to the riser, to thereby avoid the loss of seal that wouldresult if the gasket itself supported the entire shear load.

8 Claims, 6 Drawing Figures PATENTEU APR 2 2 I975 sum 2 or g FIG-5 PIPEJOINT This is a division of application Ser. No. 200,936, filed Nov. 22,I971, and now US. Pat. No. 3,744,806.

BACKGROUND OF THE INVENTION The construction of a satisfactory jointbetween two pipes sections, such as a manhole riser and intersectingfeed pipe, presents several problems. Because the joint will usually bemade in a ditch or trench where there is limited working room it isdesirable that the joint be one that is relatively easy to assemble. Atthe same time, it is necessary that the joint not only provide a sealagainst the flow of liquids out of the riser but, more importantly, thatthe infiltration of ground water into the manhole be avoided.Additionally, joints of this type are frequently subjected to rathersevere shear loads caused by shifting of the joint components withrespect to each other, as a result of which the integrity of the seal atthe joint is lost.

Various attempts have been made to cope with these problems. Forexample, one rather common type of joint utilizes an O-ring positionedabout the intersecting pipe and expanded by compression into contactwith the internal walls of the manhole. This type of construction,however, may be difficult to install under field conditions, generallyrequiring clamps and the like to compress the O-ring into sealingrelationship with the adjacent pipe surfaces.

Other types of joints utilize bushing-like resilient sleeves mounted inthe opening into the manhole riser and adapted to engage the outersurface of the intersecting pipe. While joints of this type may notrequire external clamping members to form a seal, they do require fairlyclose tolerance between the outside diameter of the intersecting pipeand the diameter of the opening through the riser and are subject toloss of seal through shifting of the joint components.

SUMMARY OF THE INVENTION The present invention provides a resilientgasket which is readily fabricated and cast in the wall of a manholeriser or the like to provide a resilient seal between an opening throughthe wall and the outside surface of an intersecting pipe. The openingthrough the riser wall is provided with an offset which defines aninwardly projecting shoulder adjacent the outer surface of the riserwall and the resilient gasket is embedded in the riser with portionsanchoring it in the wall of the riser but with a sealing portionprojecting radially inwardly of the opening past the shoulder.

Thus, the gasket engages the outside surface of the intersecting pipeand the compression of the gasket between the pipe and wall of theopening provides a tight seal, while the above noted, inwardlyprojecting shoulder provides resistance to shear loads imposed on thejoint by relative shifting of the joint components. Additionally, thepresent invention permits the formation of a tight seal even thoughthere is some deflection of the intersecting pipe from the perpendicularto the axis of the riser.

The gasket itself includes a substantially triangularly shaped mainsection with a first apex of the main section projecting inwardly of theopening and defining a sealing portion of the gasket. At a second apexof the main section adjacent the outer surface of the riser an outer lipis provided, defining with the outer face of the gasket extendingbetween the first and second apices of the main section, an outergroove. A fairly stiff wire hoop is received in this groove and serves,when the intersecting pipe is pushed through the opening in the riser,to prevent the gasket from rolling on itself and becoming disengagedfrom its embedment in the wall of the riser.

At a third apex of the main section an inner lip is provided whichdefines with an inner face of the main section extending between thefirst and third apices a groove which receives a second relatively stiffwire hoop. The gasket is also stretched over this hoop, which thenserves to prevent the gasket from rolling in the opposite direction asthe intersecting pipe is shifted outwardly to make ajoint at itsopposite end with a preceeding pipe section.

Also at the second apex of the main section an anchoring lip projects ina direction opposite to the direction of projection of the outer lip andengages in a continuous annular socket formed in that portion of theriser defining the opening therethrough. This anchoring lip has asubstantially flat face which engages a similar face of the socket andresists lateral shifting of the gasket inwardly of the manhole riser asthe intersecting pipe is pushed therethrough.

Additionally, the outer sloping face of the main section, adjacent thefirst apex thereof, is provided with a convex portion which facilitatesconformation of the resilient gasket with the outer surface of theintersecting pipe to provide a firm seal between the gasket and thepipe.

By forming the gasket with a relatively thick, triangularly, shaped,main sealing section a much more rugged seal is provided as well as onewhich is better adapted than the bushing type constructions of the priorart to prevent water infiltration through the seal. However, the offsetportion of the opening through the wall of the riser permits the sealingsection of the gasket, even though relatively thick, to deform by, ineffect, flowing, inwardly into the offset portion of the opening. Inthis way a wider range of variations from nominal pipe size may beaccommodated while still providing an effective seal.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 6 is an enlarged cross sectionalof the gasket per DESCRIPTION OF THE PREFERRED EMBODIMENT A joint inaccordance with the present invention finds particular utility injoining two sections of conduit, such as a manhole riser and anintersecting feed pipe. Thus, as seen in FIG. 1 of the drawings, amanhole riser 10 is provided with an opening 12 through a wall 14thereof through which projects an intersecting feed pipe 16.

The opening 12, as seen in FIG. 2 of the drawings, has an offset portiondefining a radially inwardly projecting annular shoulder 18 adjacentouter surface 20 of the riser 10. Additionally, another portion of thewall of the opening 12 defines a continuous slot 22 having an undercutflat face 24. Mounted in the wall of the opening 12 is a gasket 26 inthe form of an endless belt, which is shown in FIGS. 3 and 6 of thedrawings in its undistorted configuration.

The gasket 26 includes a substantially triangular shaped main section 28having first, second and third apices 30, 32 and 34, respectively. Thefirst apex 30 constitutes a radially inwardly projecting sealing portionwhich projects inwardly of the opening 12 past the inwardly projectingshoulder 18. An outer lip 36 extends from the second apex 32 of thegasket and defines with a portion of an outer face 38 extending betweenthe first and second apices 30 and 32, a continuous groove 40.

An inner lip 42 extends from the third apex 34 of the main section anddefines with an inner face 44 extending between apices 30 and 34 asecond groove 46. Additionally, an anchoring lip 48 having a flat face49 also projects from the second apex 32 of the main section and, asseen in FIGS. 2 and 5, is received in the socket 22 with the faces 24and 49 engaging each other. The outer face 38 of the main section 28 isprovided with a convex portion 50 at a point thereon adjacent the firstapex 30.

In fabricating the gasket 26 it is convenient to form it as a continuousextruded section and then cut the section to the desired length andcement the severed ends to each other to form an endless belt. In sodoing it will be apparent that the inner circumference of the gasketwill be placed in compression to the extent that there may be somebuckling and distortion of the gasket, particularly in the region of theapex 30.

Partly to overcome this and also to improve the stability of the unitwhen it is installed, as will be described in more detail below, arelatively rigid reinforcing member in the form of a wire hoop 52 ispositioned in the groove 40 by stretching the gasket 26 to extend thegasket sufficiently to overcome any buckling that may occur around theinner circumference thereof. Similarly, a second, wire endless hoop 54is received in the groove 46.

With the gasket 26 extended about the two hoops 52 and 54 the completeassembly is so positioned by means of suitable jigs that when concrete,for example, is cast about the gasket the inner face 44 thereof will besubstantially in a plane 55, as seen in FIG. 3 of the drawings. In thisway the greatest thickness of gasket material is positioned along aplane intersecting the axis of pipe 16 perpendicularly thereof, wherebymaximum sealing with the pipe surface, as indicated by cross hatching inFIG. 5, as well as the opening, is obtained.

With a manhole having the gasket embedded therein installed in thefield, a feed pipe 16 may be connected thereto as follows. Generally, astring of pipe sections will have been joined together to a point justshort of the manhole 10. The last section of pipe 16 is then positionedin the trench containing the pipe line and its end 56 thrust forwardlythrough the opening 12 in the wall of the manhole in the directionindicated by the arrow 57 in FIGS. 3 and 4 of the drawings. The end 56of the pipeline will be thrust inwardly into the riser a distancesufficient to allow its opposite end, not shown, to clear the end of thelast pipe section in the pipe line. At this point the end 56 of the pipe16 will be in the position shown in FIG. 4 of the drawings.

Thereafter, the pipe 16 is retracted in the direction indicated by thearrow 58 in FIG. 4 of the drawings to allow a joint to be made betweenthe opposite end of the pipe 16 and the adjacent end of the last pipesection in the pipe line. At this point the end 56 of the pipe willassume a position substantially as shown in FIG. 2 of the drawings.

In the process of assembling the pipe 16 in the manner described aboveseveral different forces will be acting upon the gasket 26. Thus, as thepipe 16 is thrust into the manhole 10 there will be a tendency for theouter lip 36 to lift upwardly as indicated by the arrow 60 in FIG. 5 ofthe drawings. At the same time there will be a tendency for the entiregasket to slide inwardly of the riser in the direction indicated by thearrow 62.

It will be apparent that the first of these forces is effectivelyresisted by the relatively rigid wire hoop 52 which reacts outwardlyagainst the tendency of the lip 36 to roll inwardly of the opening 12.At the same time, the flat face 49 of the anchoring lip 48, received inthe slot 22 and bearing against the complementary face 24 of theundercut portion, resists the tendency for the entire gasket to slideinwardly into the manhole.

It will also be noted that the sloping outer surface 38 facilitatesinsertion of the pipe 16 through the gasket and that the convex portion50 positioned near the apex 30 enhances the flexing of the gasket to theposition shown in FIGS. 2, 4 and 5 of the drawings. As the gasket flexesit behaves somewhat like an incompressible fluid and flows toaccommodate displacement by the pipe 16. This flowing is accommodated bythe undercut portion of the opening, as seen in FIG. 5 of the drawings,while a tight seal is formed, not only with the pipe 16 but with thesurface of the opening 12. It will also be seen that the configurationof that section of the gasket embedded in the riser and thecomplementary section of the opening 12 provide a tortuous path againstthe penetration of moisture into the manhole.

Preferably the outer face 38 of the gasket will be lubricated with asuitable lubricant, such as a vegetable soap, and when the pipe 16 isretracted in the direction indicated by the arrow 58 in FIG. 4 of thedrawings, it will merely slide along the outer face of the gasket.However, as it does, there will be a tendency for the inner lip 42 toroll inwardly in the direction indicated by the arrow 64 in FIG. 5 ofthe drawings. This tendency is effectively resisted by the relativelyrigid wire hoop 54 received in the groove 46.

From the above it will be apparent that the gasket 26 permits readyinstallation of the feed pipe 16 in the opening in the manhole riser 10.To form the joint it is merely necessary to insert the end 56 of thepipe 16 through the opening 12 to the position shown in the FIG. 4 ofthe drawing, then retract the pipe to the position as shown in FIG. 2 ofthe drawings to make the joint with the last preceding section of pipeinstalled. No external fasteners, such as nuts or bolts, are re quired,yet the relatively thick sealing section provided by the substantiallytriangular shape of the main section of the gasket provides a watertight seal around the opening through the manhole wall.

It will be noted that despite the relatively thick main section, thegasket is readily flexed because the offset portion of the opening 12accommodates flowing" of the gasket'material when a pipe 16 isinstalled. At the same time a water tight seal is formed, even thoughvariations in the intersecting pipe diameter from the nominal diameterthereof are encountered. In operation it has been found, in distinctionto prior art sealing devices of, for example, the bushing type, asatisfactory seal is provided despite variations of a half inch indiameter from nominal pipe sizes.

Additionally, the pipe 16 need not intersect the riser exactlyperpendicularly to the axis of the riser. In practice it has been foundthat with the gasket of the present invention the intersecting pipe canbe deflected as much as from the perpendicular and a good sealmaintained.

The installed assembly. will also be subjected to relatively heavy shearloads due to relative movement between the pipe and the manhole riseroccurring after installation. In prior connections of this type ashifting of the pipe 16 radially of the'opening would usually result inone portion of the gasket becoming compressed, while the Wall of thepipe separated from the gasket at a point diametrically opposed to thepoint where the greatest compression of the gasket occurs, therebypermitting infiltration and exfiltration into and out of the manhole.

In the present construction, however, the inwardly projecting shoulder18 will take the shear load generated by relative movement between thepipe 16 and the manhole riser. Thus, after an initial amount of relativemovement, the outer surface of the pipe 16 will contact the inwardlyprojecting shoulder 18 and thereby prevent separation of the outersurface of the pipe from the gasket at a point opposite that point wherethe greatest compression of the gasket has occurred.

While a variety of materials are capable of use in forming the gasket ofthe present invention, a resilient material having a Durometer hardnesson the Shore A scale of 40 to 60 is desirable with a material having ahardness of approximately 50 being optimum. Additionally, any suitablematerial may be utilized for the relatively rigid reinforcing rings 52and 54, but an 8 gage steel wire has been satisfactory.

Regardless of the specific material that is used, however, it will beseen that the present invention provides a water tight seal between apipe member and an opening through a wall which is readily fabricatedand installed and resistant to destruction by the imposition of heavyshear loads on the joint.

While the form of apparatus herein described constitutes a preferredembodiment of the invention, it is to be understood that the inventionis not limited to this precise form of apparatus, and that changes maybe made wherein without departing from the scope of the invention.

What is claimed is:

l. A joint comprising:

a. a substantially imperforate wall,

b. means defining an opening through said wall,

c. portions of said wall being offset and defining a radially inwardlyprojecting annular shoulder,

d. a resilient, annularly shaped gasket mounted in said opening,

e. said gasket in cross section including a substantially triangularmain section,

f. a first apex of said main section defining a sealing portion of saidgasket.

g. a second apex of said main section positioned in said wall adjacentan outer surface thereof,

h. an outer lip extendingfrom said second apex inwardly of said openingin said wall,

i. said outer lip and an outer face of said main section extendingbetween said first and second apexes defining a first groove,

j; a first relatively rigid reinforcing member received in said firstgroove and preventing dislocation of said second apex radially inwardlyof said'opening,

k. an inner lip extending from a third apex of said main section,

I. said inner lip and an inner face of said main section extendingbetween said first and third apexes defining a second groove,

m. a second relatively rigid reinforcing member received in said secondgroove and preventing movement of said third apex radially inwardly ofsaid opening,

n. anchoring portions of said gasket being anchored in said wallradially outwardly of said shoulder, and

0. said sealing portion of said gasket projecting radially inwardly ofsaid opening beyond said annular shoulder.

2. The joint of claim 1 wherein:

a. said outer face of said main section is convex at a point adjacentsaid first apex.

3. In a joint including a manhole riser having internal and externalsurfaces and a further surface defining a pipe receiving opening througha wall of said riser from said internal surface to said externalsurface, a pipe section intersecting said riser at substantially rightangles to the longitudinal axis thereof with an end of said pipe sectionreceived in said opening and a gasket interposed between an outsidesurface of said end of said pipe section and opposing portions of saidsurface of said riser defining said opening therethrough, theimprovement comprising:

a. a said gasket having:

i. a main section, ii. a sealing portion, and iii. an anchoring portion,

b. said surface defining said opening comprising:

i. a main section, ii. a gasket engaging section, and iii. shouldersection,

c. said shoulder section of said surface projecting radially inwardly agreater distance than said main section and said gasket engagingsection,

said anchoring portion of said gasket being imbedded in said wallradially outwardly of said main section and said shoulder section ofsaid opening defining surface,

e. the internal diameter of said shoulder section of said surface beinggreater than the external diameter of said end of said pipe and adaptedto engage said end of said pipe upon relative shifting movement of saidopening defining surface and said end of said pipe in directions otherthan parallel to the length of said pipe,

f. said main section of said gasket being disposed within said openingwith portions of said main section of said gasket disposed radiallyoutwardly of said inwardly projecting shoulder section of said openingdefining surface and interconnecting said anchoring portion and saidsealing portion of said gasket,

g. said sealing portion of said gasket projecting radially inwardly fromsaid main section of said gasket and engaging said outside surface ofsaid pipe in sealing relationship thereto, and

h. said sealing portion of said gasket, prior to insertion of said endof said pipe into said opening in said riser, projecting radiallyinwardly of said opening beyond said radially inwardly projectingshoulder section of said surface and having an internal diameter lessthan said external diameter of said pipe, whereby said sealing portionof said gasket engages said end of said pipe in said sealingrelationship thereto and maintains said sealing relationship even uponsaid relative shifting movement of said opening defining surface andsaid end of said pipe and consequent engagement of said shoulder by saidpipe.

4. The joint of claim 3 wherein:

a. said main section of said gasket is substantially triangular in crosssection, and

b. a first apex of said main section defines said sealing portion ofsaid gasket.

5. The joint of claim 4 wherein:

a. said triangular main section of said gasket includes an inner facewhich prior to said insertion of said pipe end lies in a plane extendingsubstantially parallel to the longitudinal axis of said manhole riser.

6. The joint of claim 4 further comprising:

a. a second apex of said main section disposed adjacent said externalsurface of said riser,

b. an outer lip of said gasket projecting from said second apex inwardlyof said opening defining surface in said wall of said riser,

c. said outer lip and an outer face of said main section extendingbetween said first and second apices defining a first groove, and

d. a first, relatively rigid reinforcing hoop received in said firstgroove and preventing dislocation of said second apex of said gasketradially inwardly of said opening.

7. The joint of claim 6 wherein:

a. said anchoring portion of said gasket includes an anchoring lipprojecting from said second apex of said gasket into said riser wall ina direction substantially opposite to the direction of projection ofsaid outer lip, and

b. means defining a socket extending radially outwardly from saidopening defining surface and receiving said anchoring lip.

8. The joint of claim 4 wherein:

a. said substantially triangular main section of said gasket includes anouter face sloping radially outwardly of said opening from said firstapex toward said external surface of said wall, and

b. said outer face is convex adjacent said first apex.

1. A joint comprising: a. a substantially imperforate wall, b. meansdefining an opening through said wall, c. portions of said wall beingoffset and defining a radially inwardly projecting annular shoulder, d.a resilient, annularly shaped gasket mounted in said opening, e. saidgasket in cross section including a substantially triangular mainsection, f. a first apex of said main section defining a sealing portionof said gasket. g. a second apex of said main section positioned in saidwall adjacent an outer surface thereof, h. an outer lip extending fromsaid second apex inwardly of said opening in said wall, i. said outerlip and an outer face of said main section extending between said firstand second apexes defining a first groove, j. a first relatively rigidreinforcing member received in said first groove and preventingdislocation of said second apex radially inwardly of said opening, k. aninner lip extending from a third apex of said main section, l. saidinner lip and an inner face of said main section extending between saidfirst and third apexes defining a second groove, m. a second relativelyrigid reinforcing member received in said second groove and preventingmovement of said third apex radially inwardly of said opening, n.anchoring portions of said gasket being anchored in said wall radiallyoutwardly of said shoulder, and o. said sealing portion of said gasketprojecting radially inwardly of said opening beyond said annularshoulder.
 1. A joint comprising: a. a substantially imperforate wall, b.means defining an opening through said wall, c. portions of said wallbeing offset and defining a radially inwardly projecting annularshoulder, d. a resilient, annularly shaped gasket mounted in saidopening, e. said gasket in cross section including a substantiallytriangular main section, f. a first apex of said main section defining asealing portion of said gasket. g. a second apex of said main sectionpositioned in said wall adjacent an outer surface thereof, h. an outerlip extending from said second apex inwardly of said opening in saidwall, i. said outer lip and an outer face of said main section extendingbetween said first and second apexes defining a first groove, j. a firstrelatively rigid reinforcing member received in said first groove andpreventing dislocation of said second apex radially inwardly of saidopening, k. an inner lip extending from a third apex of said mainsection, l. said inner lip and an inner face of said main sectionextending between said first and third apexes defining a second groove,m. a second relatively rigid reinforcing member received in said secondgroove and preventing movement of said third apex radially inwardly ofsaid opening, n. anchoring portions of said gasket being anchored insaid wall radially outwardly of said shoulder, and o. said sealingportion of said gasket projecting radially inwardly of said openingbeyond said annular shoulder.
 2. The joint of claim 1 wherein: a. saidouter face of said main section is convex at a point adjacent said firstapex.
 3. In a joint including a manhole riser having internal andexternal surfaces and a further surface defining a pipe receivingopening through a wall of said riser from said internal surface to saidexternal surface, a pipe section intersecting said riser atsubstantially right angles to the longitudinal axis thereof with an endof said pipe section received in said opening and a gasket interposedbetween an outside surface of said end of said pipe section anD opposingportions of said surface of said riser defining said openingtherethrough, the improvement comprising: a. a said gasket having: i. amain section, ii. a sealing portion, and iii. an anchoring portion, b.said surface defining said opening comprising: i. a main section, ii. agasket engaging section, and iii. shoulder section, c. said shouldersection of said surface projecting radially inwardly a greater distancethan said main section and said gasket engaging section, d. saidanchoring portion of said gasket being imbedded in said wall radiallyoutwardly of said main section and said shoulder section of said openingdefining surface, e. the internal diameter of said shoulder section ofsaid surface being greater than the external diameter of said end ofsaid pipe and adapted to engage said end of said pipe upon relativeshifting movement of said opening defining surface and said end of saidpipe in directions other than parallel to the length of said pipe, f.said main section of said gasket being disposed within said opening withportions of said main section of said gasket disposed radially outwardlyof said inwardly projecting shoulder section of said opening definingsurface and interconnecting said anchoring portion and said sealingportion of said gasket, g. said sealing portion of said gasketprojecting radially inwardly from said main section of said gasket andengaging said outside surface of said pipe in sealing relationshipthereto, and h. said sealing portion of said gasket, prior to insertionof said end of said pipe into said opening in said riser, projectingradially inwardly of said opening beyond said radially inwardlyprojecting shoulder section of said surface and having an internaldiameter less than said external diameter of said pipe, whereby saidsealing portion of said gasket engages said end of said pipe in saidsealing relationship thereto and maintains said sealing relationshipeven upon said relative shifting movement of said opening definingsurface and said end of said pipe and consequent engagement of saidshoulder by said pipe.
 4. The joint of claim 3 wherein: a. said mainsection of said gasket is substantially triangular in cross section, andb. a first apex of said main section defines said sealing portion ofsaid gasket.
 5. The joint of claim 4 wherein: a. said triangular mainsection of said gasket includes an inner face which prior to saidinsertion of said pipe end lies in a plane extending substantiallyparallel to the longitudinal axis of said manhole riser.
 6. The joint ofclaim 4 further comprising: a. a second apex of said main sectiondisposed adjacent said external surface of said riser, b. an outer lipof said gasket projecting from said second apex inwardly of said openingdefining surface in said wall of said riser, c. said outer lip and anouter face of said main section extending between said first and secondapices defining a first groove, and d. a first, relatively rigidreinforcing hoop received in said first groove and preventingdislocation of said second apex of said gasket radially inwardly of saidopening.
 7. The joint of claim 6 wherein: a. said anchoring portion ofsaid gasket includes an anchoring lip projecting from said second apexof said gasket into said riser wall in a direction substantiallyopposite to the direction of projection of said outer lip, and b. meansdefining a socket extending radially outwardly from said openingdefining surface and receiving said anchoring lip.